Interstate 5 expansion plans, at a glance

• Cost estimated at up to $3.5 billion, up from $3.3 billion two years ago

• Crosses through six cities and over six lagoons

• First phase would add 2 lanes from Manchester Ave. to State Route 78

• Estimated start of construction is 2015

Source: Caltrans

The much debated and delayed plans to widen Interstate 5 from La Jolla to Camp Pendleton should reach a critical junction by summer 2013. That’s when the California Department of Transportation expects to finish the multibillion dollar project’s final environmental plans and submit a permit application to the powerful California Coastal Commission, officials said last week.

As recently as last year, Caltrans had said expansion could start in 2013 on North County’s aging, crowded stretch of I-5. But construction is now slated to start in 2015, at the earliest, and 2013 will be devoted to reaching planning milestones, not pouring concrete, officials said.

Plans call for adding four new express lanes along the center of the freeway, at a cost of up to $3.5 billion. That amount does not account for inflation and is up from an estimated $3.3 billion two years ago. The lanes would be open to carpoolers, buses, select clean fuel cars, motorcycles and fee-paying solo drivers.

While seeking regulatory approvals in 2013 will be critical to the project’s future, some drivers who use I-5 just want the gridlock to clear. And fast.

“I think the faster they get (the expansion) done, the better,” said George Cortez, an Oceanside preschool teacher, stopping to chat about the freeway with a reporter last week.

Cortez said he uses I-5 usually just on the weekends, but even then it can be painfully slow, noting he tries “to avoid it.”

Project opponents, many who say new freeway lanes won’t solve the region’s traffic problems, have slowed the pace of expansion plans.

Concerns about the project’s environmental effects on the six lagoons it crosses led Caltrans to complete additional environmental studies last year, pushing back the agency’s timeline, officials said. It now plans to build longer freeway bridges over three lagoons, to allow more water to flow into the lagoons, improving their health.

Those new documents will be part of a $6.5 billion package of I-5 freeway widening, coastal rail expansion and environmental preservation reviewed by the Coastal Commission, which has authority over development along California’s coastline. Caltrans officials expect the permit application to be submitted by summer 2013.

By February or March 2013, Caltrans plans to release a second draft of that package, described as a long-term blueprint for North County’s coastal corridor and formally known as the Public Works Plan. A 45-day public comment period will follow.

None of the projects is expected to materialize overnight. The freeway widening, for example, is scheduled over four decades with construction on the first phase (two lanes from Manchester Avenue in Encinitas to state Route 78 in Oceanside) starting in spring 2015.